Author Topic: Courtesy Lamp wiring, door switches, dash harness  (Read 907 times)

Offline Angela

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Courtesy Lamp wiring, door switches, dash harness
« on: December 18, 2022, 07:57:52 PM »
Does anyone have a picture, schematic or wiring aid which may help me understand:
(1) Which wires feed the under dash courtesy lights on driver and passenger sides of the car? I don't find any such wire as part of the dash harness and I suspect there's some sort of additional harness that taps into the courtesy light switch plugs.
(2) Where do the door light and speaker harnesses connect into the dash harness?
(3) Why does the driver's side door courtesy light switch connector have three (3) prongs whereas the passenger side switch connector has the expected two (2) prongs? 

The above pertains to a 1970 Dearborn-built Mach1 built the first week October of '69.

I have the assembly and wiring manuals but remain confused re the above.
Thanks!

Offline midlife

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Re: Courtesy Lamp wiring, door switches, dash harness
« Reply #1 on: December 18, 2022, 10:17:37 PM »
Does anyone have a picture, schematic or wiring aid which may help me understand:
(1) Which wires feed the under dash courtesy lights on driver and passenger sides of the car? I don't find any such wire as part of the dash harness and I suspect there's some sort of additional harness that taps into the courtesy light switch plugs.
(2) Where do the door light and speaker harnesses connect into the dash harness?
(3) Why does the driver's side door courtesy light switch connector have three (3) prongs whereas the passenger side switch connector has the expected two (2) prongs? 

The above pertains to a 1970 Dearborn-built Mach1 built the first week October of '69.

I have the assembly and wiring manuals but remain confused re the above.
Thanks!
1. 1970 is different than 1969, in that there is a separate underdash courtesy light harness that taps into the passenger side door jamb connector with a pigtail and runs all the way across to the driver's side.  At each side, there is a female spade lead and a separate female bullet plug.  The spade lead is for the separate lamp assemblies.2. The female plug is for extensions to the passenger sail panel courtesy light (which also has a female pigtail bullet plug) that either can be used as feeds for the door lamps.  The driver's side plug is for the door lamp.3. The third wire is for the door ajar buzzer signal when the key is engaged.
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Offline Angela

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Re: Courtesy Lamp wiring, door switches, dash harness
« Reply #2 on: December 19, 2022, 03:06:36 AM »
Thanks Midlife, much appreciated. Do you happen to know if the 1970-only courtesy lamp extension is reproduced? Or, perhaps you have one you're willing to sell? Perhaps you have a picture of this harness? I do not believe I've seen this harness. I thought the courtesy lamps were somehow powered by the Mach1 door harnesses, but I haven't figured that out.

Concerning the driver's side courtesy lamp switch connector... I'm referring to the fact the connector at the door jamb physically has three male prongs inside the socket whereas all of the door jamb switches I've seen only have two female connections. I'm confused.

Offline midlife

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Re: Courtesy Lamp wiring, door switches, dash harness
« Reply #3 on: December 19, 2022, 11:22:30 AM »
They are not reproduced, as far as I know.  I have only remnants of these harnesses at the moment.
So why 3 pins instead of 2?  As I said, there's now an extra pin/wire for the door ajar warning system.  The wire is red in color and the relay is on the passe3nger side mated with a black wire.  Some relays have a third wire in the middle post of the relay, which is a run-only line.
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Offline 70cj428

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Re: Courtesy Lamp wiring, door switches, dash harness
« Reply #4 on: December 22, 2022, 03:35:37 PM »
Is your car optioned with the convience group ?   That changes the courtesy lamp wiring ...